1. Field
The disclosed concept relates generally to electrical switching apparatus and, more particularly, to electrical switching apparatus, such as circuit breakers. The disclosed concept also relates to a modular levering assembly for electrical switching apparatuses.
2. Background Information
Electrical switching apparatus used in power distribution systems are often mounted within a switchgear enclosure either individually or in combination with other switchgear (e.g., without limitation, circuit switching devices and circuit interrupters such as, but not limited to, circuit breakers, contactors, motor starters, motor controllers and other load controllers).
Some electrical switching apparatus such as, for example, some medium-voltage and low-voltage circuit breakers, can be relatively large. In order to facilitate movement (e.g., installation; removal; maintenance), some electrical switching apparatuses are commonly coupled to draw-out mechanisms which permit such electrical switching apparatuses to be drawn out of the switchgear enclosure. Accordingly, such electrical switching apparatuses are commonly known in the art as “draw-out” circuit breakers. The electrical switching apparatus may be further supported within a draw-out frame, commonly known in the art as a cassette or chassis. The switchgear enclosure generally includes a number of cells, with each cell being structured to receive a corresponding electrical switching apparatus. The draw-out mechanism includes, for example, a combination of rails and rollers coupled to one or the other, or both, of the sidewalls of the cell and the sides of the corresponding electrical switching apparatus and/or cassette, which is to be drawn into and out of the cell. A levering in assembly (sometimes referred to as a “lev-in” device), which among other components includes a drive screw and drive rack, facilitates levering the electrical switching apparatus into the cassette. Draw-out electrical switching apparatuses are described in further detail, for example, in commonly assigned U.S. Pat. No. 7,019,229. The levering in assemblies are sized to correspond to the electrical switching apparatus to which they are coupled. That is, an electrical switching apparatus has a width, which is typically a function of the number of poles which the electrical switching apparatus has. That is, the greater the number of poles, the wider the electrical switching apparatus. A levering in assembly, in a common embodiment, includes a drive shaft with gears on each end that engage the racking members disposed on the lateral sides of the cassette. Thus, the levering in assembly has a width substantially similar to the electrical switching apparatus. This is a disadvantage in that for each size electrical switching apparatus, a corresponding levering in assembly must be made.
There is, therefore, room for improvement in electrical switching apparatus, such as circuit breakers, and in levering assemblies. That is, there is a need for a levering in assembly that may be adapted for use with electrical switching apparatuses having different sizes. There is a further need for such a levering in assembly to operate with cassettes and other hardware presently in use.